JP7719677B2 - Water jet injection fluid - Google Patents

Description

This invention relates to a water jet spray liquid, such as that used in water jet construction methods, in which the liquid is sprayed onto concrete structures to perform various processes.

BACKGROUND ART Conventionally, it has been known to use a water jet method to remove the surface layer of a concrete structure for repairing the concrete structure, i.e., to perform so-called chipping work.
Specifically, the water jet method is a method in which a spray liquid such as water is pressurized to ultra-high pressure and sprayed from a nozzle toward a concrete structure, and the concrete structure is processed by the collision energy of the jet when the spray liquid collides with the concrete structure.

As an example of equipment that makes this type of water jet construction method possible, Patent Document 1 discloses a water jet device that is composed of a water jet pump that pressurizes the spray liquid to ultra-high pressure, a base on which a nozzle is mounted, and rails that movably support the base and can be attached to the concrete structure.

Incidentally, to improve the processing efficiency of concrete structures using the water jet method, one possible solution would be to replace the pump unit of the water jet device (the water jet pump in Patent Document 1) and spray the liquid at a higher pressure.

However, in this case, the pump unit would become too large and there was a risk that it would not be possible to replace the existing pump unit. As a result, with water jet devices such as those described in Patent Document 1, there was a problem in that it was not easy to improve the processing efficiency of the water jet method.

Japanese Patent Application Laid-Open No. 2020-133316

In view of the above-mentioned problems, the present invention aims to provide a water jet spray liquid that can improve processing efficiency in water jet processing.

This invention is a water jet spray liquid that is sprayed through a nozzle toward a concrete structure, characterized in that the liquid is an aqueous solution containing a predetermined amount of a water-soluble admixture that increases the collision energy of the jet sprayed from the nozzle, and the water-soluble admixture is a set-retarding organic compound that delays the setting of cement .
The collision energy refers to the energy possessed by the water jetting liquid when it collides with the concrete structure.

According to this invention, the water-soluble admixture allows the impact energy of the jet when it strikes a concrete structure to be greater than that of water, so the water jet spray liquid can improve the processing efficiency of water jet construction methods, even when using, for example, an existing pump unit.

Furthermore, since the water-soluble admixture is a set-retarding organic compound that delays cement setting, the set-retarding organic compound has good solubility in water and can increase the specific gravity of the aqueous solution compared to water.

Therefore, the set retarding organic compound can increase the collision energy of the jet when it collides with a concrete structure compared to water.
As a result, the water jet spray liquid can improve the processing efficiency in the water jet method, even when an existing pump unit is used, for example.

In addition, even if the slag remaining after processing a concrete structure contains unhydrated cement, the water jet spray liquid can delay the setting time of the unhydrated cement by using the set-retarding organic compound. Therefore, the water jet spray liquid can reduce the effort required to clean floors and road surfaces and remove waste liquid containing slag that has adhered to the floors and road surfaces.

In another embodiment of the present invention, the set retarding organic compound may be at least one of an oxycarboxylic acid, an oxycarboxylic acid salt, and a sugar.
According to this configuration, since the hydroxycarboxylic acid-based compounds, hydroxycarboxylic acid salt-based compounds, and sugars all have high solubility in water, the specific gravity of the aqueous solution can be made larger.

Therefore, the set retarding organic compound can reliably increase the collision energy of the jet when it collides with a concrete structure, thereby enabling the water jet spray liquid to further improve the processing efficiency in the water jet method.

In addition, the viscosity of the aqueous solution of hydroxycarboxylic acids, hydroxycarboxylic acid salts, and sugars can be made approximately equal to that of water, so even if the water jet spray liquid adheres to a floor or road surface, it can prevent the floor or road surface from becoming slippery.

In another embodiment of the present invention, the density of the aqueous solution is 1.02 g/cm ³ A predetermined amount of the set retarding organic compound may be dissolved.
This configuration reliably increases the specific gravity of the aqueous solution, thereby reliably increasing the collision energy of the jet of the set retarding organic compound when it collides with a concrete structure, thereby further improving the processing efficiency of the water jet method.

In another embodiment of the present invention, a predetermined amount of the set retarding organic compound may be dissolved to provide a setting time of 24 hours or more.
The setting time refers to the reaction time of the hydration reaction, or the initiation time of the hydration reaction, or the initiation time and reaction time of the hydration reaction.

In an embodiment of the present invention, the water-soluble admixture may be a surfactant.
The surfactant refers to, for example, a shrinkage reducing agent for concrete.
With this configuration, the surfactant reduces the surface tension of the water jet spray liquid compared to water and reduces the friction at the interface, thereby reducing the frictional resistance between the water jet spray liquid and the nozzle compared to water, and enabling the water jet spray liquid to be discharged at a faster speed.

Furthermore, the surfactant easily breaks down the jet of water sprayed from the nozzle into fine particles, and therefore can prevent the speed of the jet of water from decreasing due to air resistance.
As a result, the jet ejected from the nozzle at a high discharge speed collides with the concrete structure without a significant decrease in speed, and the surfactant can increase the collision energy of the jet when it collides with the concrete structure compared to water.

In addition, the reduced surface tension improves the wettability of the water jet spray liquid, so when the water jet spray liquid adheres to the surface of a concrete structure, the water jet spray liquid can thin the water film that forms on the surface of the concrete structure. Therefore, when the water jet spray liquid sprayed from the nozzle collides with the concrete structure through the water film, the collision energy of the jet can be prevented from being absorbed by the water film that forms on the concrete structure.

Furthermore, surfactants are used in a variety of fields and applications and are relatively easy to obtain, so surfactants can stabilize the quality of water jet spray liquids compared to dissolving admixtures, which are difficult to obtain.
Therefore, the water jet spray liquid can stably improve the processing efficiency in the water jet method, even when using an existing pump unit, for example.

In another embodiment of the present invention, the surfactant may contain a polyalkylene glycol derivative as a main component.
The polyalkylene glycol derivatives are the main components of shrinkage reducing agents for concrete, and include, for example, alkylene oxide adducts of lower alcohols, polyether derivatives, glycol ether derivatives, and the like.
According to this configuration, since the polyalkylene glycol derivative has good solubility even in powder form, for example, the viscosity of the water jet ejection liquid can be made substantially equal to the viscosity of water.

Furthermore, in the case of a water jet injection fluid in which powdered polyacrylamide polymer is dissolved in water to improve processing efficiency, for example, polyacrylamide polymer is difficult to dissolve in water, so clumps of polyacrylamide polymer form in the aqueous solution and the viscosity of the aqueous solution becomes higher than that of water.

In contrast, polyalkylene glycol derivatives are less likely to form lumps in aqueous solutions due to their good solubility. Therefore, polyalkylene glycol derivatives can more homogenize the surface tension of the water jet spray liquid and more stabilize the viscosity of the water jet spray liquid.

For example, if an aqueous solution has a higher viscosity than water, adhering to a floor or road surface will make the floor or road surface slippery. For this reason, when a highly viscous aqueous solution adheres to a floor or road surface, it is necessary to wash the floor or road surface with a large amount of water to remove the aqueous solution.

In contrast, water jet spray liquid containing a surfactant whose main component is a polyalkylene glycol derivative has a viscosity roughly equivalent to that of water, and therefore, even if it adheres to a floor or road surface, it can prevent the floor or road surface from becoming slippery.
Therefore, the water jet spray liquid can be used to clean floors and roads, reducing the effort required to remove scattered aqueous solutions and waste liquids after processing concrete structures.

In another embodiment of the present invention, a predetermined amount of the surfactant may be dissolved so that the surface tension is 90% or less of that of water.
This configuration reliably increases the speed of the jet sprayed from the nozzle, and the surfactant can increase the collision energy of the jet when it hits a concrete structure, thereby further improving the processing efficiency of the water jet method.

With this configuration, the water jet spray liquid can sufficiently delay the setting of unhydrated cement contained in the slag. Therefore, the water jet spray liquid can easily ensure the time required to treat the slag.

The present invention provides a water jet spray liquid that can improve processing efficiency in water jet processing.

FIG. 1 is an explanatory diagram illustrating an outline of a water jet device. FIG. 2 is an explanatory diagram illustrating the properties of a polyalkylene glycol derivative. FIG. 1 is an explanatory diagram illustrating the properties of sodium gluconate. FIG. 1 is an explanatory diagram illustrating an outline of a chipping test.

An embodiment of the present invention will be described below with reference to the drawings.
In this embodiment, a water jet spray liquid such as that used in a water jet method in which the liquid is sprayed onto a concrete structure C to perform various processes such as drilling, cutting, and chipping will be described.

First, a water jet device 1 used in the water jet method will be briefly described with reference to FIG. 1 which shows an explanatory diagram for explaining the outline of the water jet device 1.
As shown in Figure 1, the water jet device 1 includes a water tank 2 that stores water jet injection liquid W, a pump unit 4 that is mounted on a vehicle 3, and an upstream hose 5 that connects the water tank 2 to the pump unit 4.

Furthermore, as shown in FIG. 1, the water jet device 1 includes a downstream hose 6 extending from the pump unit 4, a spray unit 7 connected to the tip of the downstream hose 6, and a control unit 8 that controls the operation of the spray unit 7.

Specifically, the pump unit 4 is, for example, an engine-driven high-pressure pump, and has the function of sucking up the water jet injection liquid W stored in the water storage tank 2 via the upstream hose 5.

Furthermore, the pump unit 4 has the function of pressurizing the sucked-up water jet injection liquid W to ultra-high pressure, and the function of pumping the pressurized water jet injection liquid W to the injection unit 7 via the downstream hose 6.

As shown in Figure 1, the spray unit 7 is attached to the concrete structure C and includes a nozzle 71 that sprays the water jet spray liquid W supplied via the downstream hose 6 at ultra-high pressure toward the surface of the concrete structure C to be processed. The spray unit 7 is configured to move the nozzle 71 in two mutually perpendicular directions that are approximately parallel to the surface of the concrete structure C to be processed.

More specifically, although detailed illustrations are omitted, the injection unit 7 includes a rail portion 72 that is attached to the concrete structure C, a nozzle 71, and a main body portion 73 to which the downstream hose 6 is connected.

The rail section 72 is attached to the surface to be processed, for example, of the concrete structure C, and is configured in a roughly H-shape with a pair of elongated first rails spaced a predetermined distance apart in the short direction, and a long second rail arranged so that its longitudinal direction roughly coincides with the short direction of the first rails.

Furthermore, the rail section 72 is provided with a rail drive section that moves the second rail along the first rail.
On the other hand, the main body 73 is attached so as to be movable on, for example, the second rail of the rail portion 72, and is provided with a main body drive unit (not shown) for moving on the second rail.

The control unit 8 is electrically connected to the injection unit 7 and has the functions of supplying power to the main body 73, controlling the operation of the rail portion 72, and controlling the operation of the main body 73. As shown in Figure 1, the control unit 8 operates using power from the generator 9, and supplies power from the generator 9 to the injection unit 7.

The water jet spray liquid W is an aqueous solution containing a predetermined amount of dissolved water-soluble additive that increases the collision energy of the jet sprayed from the nozzle 71. Here, the collision energy refers to the energy possessed by the water jet spray liquid W when it collides with the concrete structure C.

In this embodiment, the water-soluble admixture is a surfactant, a set-retarding organic compound that has the ability to delay the setting time of cement, or both a surfactant and a set-retarding organic compound.

Next, the water jet injection liquid W described above, including the water jet injection liquids of Examples 1 to 3 of the present invention and the water jet injection liquid of the comparative example, will be described in further detail using Tables 1 and 2, and Figures 2 and 3.

Table 1 shows a list of the components of the water jet spray liquid, and Table 2 shows a list of the properties of the water jet spray liquid.
FIG. 2 is an explanatory diagram illustrating the properties of the polyalkylene glycol derivative, and FIG. 3 is an explanatory diagram illustrating the properties of sodium gluconate.

The water jet spray liquids of Examples 1 to 3 shown in Table 2 were obtained by pouring the solvent and solute into a bucket, homogenizing them using a hand mixer, and measuring the properties of 100 L of the resulting aqueous solution.

In Table 2, the values in the concentration column indicate the concentration of the solute in the aqueous solution, the values in the density column indicate the density of the aqueous solution at 20°C as measured using a hydrometer, the values in the viscosity column indicate the viscosity of the aqueous solution at 20°C as measured using a B-type rotational viscometer (rotor rotation speed: 20 rpm), and the values in the surface tension column indicate the surface tension of the aqueous solution at 25°C as measured using the plate method. Furthermore, the pump suction performance in Table 2 shows the ease with which the pump unit 4 sucks in the water jet spray liquid, compared with a comparative example (tap water).

The water jet spray liquid of the comparative example was tap water, as shown in Table 1. More specifically, the water jet spray liquid of the comparative example was tap water with a density of 1.00 g/cm ³ , a viscosity of 1.0 mPa·sec, and a surface tension of 72 mN/m, as shown in Table 2.

Furthermore, as shown in Table 1, the water jet spray liquid in Example 1 is an aqueous solution containing tap water as a solvent and a surfactant as a solute, and is produced by dissolving a powder of a polyalkylene glycol derivative, a type of surfactant that has good solubility in tap water, in tap water.

In Example 1, Sudox (registered trademark) DF-40 manufactured by NOF Corporation, which contains a polyoxyalkylene compound as its main component, was used as the polyalkylene glycol derivative.

This polyalkylene glycol derivative is used as the main component of a shrinkage reducing agent, which is one of the admixtures for concrete. Therefore, when dissolved in a solvent, the polyalkylene glycol derivative has the effect of reducing the surface tension of the solvent.
Furthermore, due to its good solubility, the polyalkylene glycol derivative is less likely to form lumps in an aqueous solution, and has the effect of suppressing an increase in the viscosity of the aqueous solution.

For example, as shown in Figure 2, an aqueous solution of the aforementioned NOF Corporation's Sudox (registered trademark) DF-40 dissolved in pure water has a surface tension of 90% or less of the surface tension of pure water, i.e., 65 mN/m or less, when the concentration of the polyalkylene glycol derivative is 0.05% or more.

More specifically, the water jet spray liquid of Example 1 is an aqueous solution having a polyalkylene glycol derivative concentration of 0.05%, a density of 1.00 g/cm ³ , a viscosity of 1.0 mPa·sec, and a surface tension of 63 mN/m, as shown in Table 2.

As such, the water jet spray liquid of Example 1 has the same density and viscosity as the comparative example (tap water), and its surface tension is 90% or less of that of the comparative example. Furthermore, the water jet spray liquid of Example 1 has the same pump suction properties as the comparative example, and does not foam.

Furthermore, as shown in Table 1, the water jet spray liquid of Example 2 is an aqueous solution containing tap water as a solvent and a set-retardant organic compound as a solute, and is produced by dissolving sodium gluconate powder, which has good solubility in tap water, as the set-retardant organic compound.

Sodium gluconate is an organic oxycarboxylate compound used as a component of concrete admixtures, and has the property of delaying the setting time, which is the time when the hydration reaction begins.
For example, sodium gluconate added to a cement paste with a water-cement ratio W/C of 4.0 has the property of delaying the setting time of the cement paste by 24 hours or more when its concentration is 0.025% or more, as shown in Figure 3(a).

The setting time can be, for example, the time measured in accordance with the "Test Method for Setting Time of Concrete" in the Japanese Industrial Standards, JIS A1147, or the "time t1 at which the heat release rate of the alite reaction in cement reaches its maximum, as measured by a conduction calorimeter," as described in "Calorimetric Measurement and the Performance of Cement and Concrete" by Etsuro Sakai (Thermal Measurement, Journal of the Japan Society of Thermal Measurement, Vol. 39, pp. 15-21, published in 2012).

Furthermore, sodium gluconate has the property of being highly soluble in water, making it easy to obtain a high-density aqueous solution.
For example, as shown in FIG. 3(b), an aqueous solution containing dissolved sodium gluconate has a characteristic that the density of the aqueous solution becomes 1.02 g/cm ³ or more when the concentration of sodium gluconate is 4.0% or more.

More specifically, the water jet spray liquid of Example 2 is an aqueous solution having a sodium gluconate concentration of 4.0%, a density of 1.02 g/cm ³ , a viscosity of 1.1 mPa·sec, and a surface tension of 72 mN/m, as shown in Table 2.

As such, the water jet spray liquid of Example 2, with a sodium gluconate concentration of 4.0%, has the property of delaying the onset of the hydration reaction with unhydrated cement by 24 hours or more. Furthermore, the density and viscosity of the water jet spray liquid of Example 2 are slightly increased to a level that is roughly equivalent to that of the comparative example (tap water), and the surface tension is equivalent to that of the comparative example (tap water). Additionally, although the water jet spray liquid of Example 2 foams slightly, it has the same pump suction properties as the comparative example.

The water jet spray liquid of Example 3 is an aqueous solution containing tap water as a solvent and a surfactant and a set-retardant organic compound as solutes, as shown in Table 1, and is produced by dissolving the polyalkylene glycol derivative powder and sodium gluconate powder described above.

More specifically, the water jet spray liquid of Example 3 is an aqueous solution having a polyalkylene glycol derivative concentration of 0.1%, a sodium gluconate concentration of 4.0%, a density of 1.02 g/cm ³ , a viscosity of 1.1 mPa·sec, and a surface tension of 63 mN/m, as shown in Table 2.

As such, the water jet spray liquid of Example 3, with a sodium gluconate concentration of 4.0%, has the property of delaying the onset of the hydration reaction with unhydrated cement by 24 hours or more. Furthermore, the density and viscosity of the water jet spray liquid of Example 3 are slightly increased to a degree that is roughly equivalent to that of the comparative example (tap water), and the surface tension is 90% or less of that of the comparative example. Additionally, the water jet spray liquid of Example 3 has pump suction properties equivalent to that of the comparative example, and does not foam.

Next, we will explain the results of a comparative test in which chipping was performed on a specimen S of concrete structure C (see Figure 4) using the water jet spray liquid of the comparative example described above and the water jet spray liquid of Examples 1 to 3.

First, the specimen S was a flat plate made of concrete mixture 27-18-20N, 0.2 m thick, and 1.7 m square. The compressive strength of the specimen S before the test was approximately 30 N/ ^mm² .
As shown in FIG. 4, which is an explanatory diagram for explaining the outline of the chipping test, this specimen S was placed so that its main surface was approximately vertical, and of the opposing main surfaces, the formwork surface was used as the target surface for the chipping operation.

The pump unit 4 of the water jet device 1 had a maximum pressure of 240 MPa and a maximum water flow rate of 25 L/min. Furthermore, as shown in Figure 4, the spray unit 7 of the water jet device 1 is an elevation angle spray type in which multiple nozzles 71 are mounted on a table 73a that rotates around the horizontal axis, and the nozzles 71 are inclined relative to the horizontal. The water jet device 1 was calibrated for spray pressure and nozzle distance immediately before testing.

Using the water jet device 1 described above, the water jet spray liquids of the comparative example and Examples 1 to 3 were sprayed onto an area of 100 mm x 150 mm of the test piece S to perform chipping. During this process, the main body 73 of the spray unit 7 was moved back and forth once per minute.

Then, using a 3D scanner, the cutting depth of the chipped specimen S was measured using a mesh with 1 cm intervals, and the cutting volume, which is the volume of the part chipped by the water jet spray fluid, the minimum cutting depth, which is the shallowest cutting depth, and the variation in cutting depth (coefficient of variation ratio) were calculated (see Table 3).

In Table 3, the values in the cutting volume column, the minimum cutting depth column, and the depth variation column are set to the result of the chipping test using the water jet spray fluid of the comparative example as "1.00," and the chipping test results of the water jet spray fluids of Examples 1 to 3 are shown as a ratio to the comparative example.

Table 3 shows that the water jet spray fluid of Example 1 has a cutting volume 1.05 times that of the comparative example and a minimum cutting depth 1.10 times that of the comparative example, which indicates that the collision energy of the jet when it collides with concrete structure C is increased compared to the comparative example.

Furthermore, since the variation in cutting depth of the water jet spray liquid of Example 1 is reduced to 0.85 times that of the comparative example, it can be said that the jet sprayed from the nozzle 71 is refined by the polyalkylene glycol derivative.
On the other hand, the water jet spray liquid of Example 1 showed a result in which the slag solidified after 24 hours, similar to the comparative example.

Furthermore, the water jet spray fluid of Example 2 had the same variation in cutting depth as the comparative example, but the cutting volume was 1.10 times that of the comparative example, and the minimum cutting depth was 1.20 times that of the comparative example, which shows that the collision energy of the jet when it collided with concrete structure C was increased compared to the comparative example and Example 1.

In addition, the slag produced by the water jet spray liquid in Example 2 did not solidify after 24 hours, which suggests that the coagulation delay effect of sodium gluconate significantly delayed the coagulation time.

Furthermore, the water jet spray fluid of Example 3 has a cutting volume that is 1.10 times that of the comparative example, and a minimum cutting depth that is 1.25 times that of the comparative example, which shows that the collision energy of the jet when it collides with concrete structure C is increased compared to the comparative example.

In particular, the water jet spray liquid of Example 3 has a minimum cutting depth greater than those of Examples 1 and 2, which means that the impact energy of the jet when it collides with the concrete structure C is improved due to the synergistic effect of the reduced surface tension caused by the polyalkylene glycol derivative and the increased density caused by sodium gluconate.

Furthermore, the water jet spray liquid of Example 3 has a cutting depth variation reduced to 0.90 times that of the comparative example, which means that the jet sprayed from the nozzle 71 is refined by the polyalkylene glycol derivative.
In addition, the slag produced by the water jet spray liquid of Example 3 was not solidified after 24 hours, and thus, as in Example 2, the setting time was delayed due to the setting retarding effect of sodium gluconate.

As such, it can be seen that the water jet spray liquids of Examples 1 to 3 are able to increase the collision energy of the jet when it collides with the concrete structure C compared to the comparative example, regardless of the performance of the pump unit 4, thereby improving the processing efficiency of the concrete structure C in the water jet method.

As described above, the water jet spray liquid W of this embodiment is a spray liquid that is sprayed through the nozzle 71 toward the concrete structure C in the water jet method.
The water jet spray liquid W is an aqueous solution in which a predetermined amount of a water-soluble additive that increases the collision energy of the jet sprayed from the nozzle 71 is dissolved.

With this configuration, the water-soluble admixture increases the impact energy of the jet when it collides with the concrete structure C compared to the comparative example (tap water). Therefore, the water jet spray liquid W can improve the processing efficiency of the water jet method, even when using, for example, an existing pump unit 4.

The water jet spray liquid W in Examples 1 and 3 contains a surfactant dissolved therein as a water-soluble admixture.
With this configuration, the surfactant reduces the surface tension of the water jet ejection liquid W compared to water and reduces the friction at the interface, thereby reducing the frictional resistance between the water jet ejection liquid W and the nozzle 71 compared to water, thereby increasing the ejection speed of the water jet ejection liquid W.

Furthermore, the surfactant easily breaks down the jet of water sprayed from the nozzle 71 into fine particles, which can prevent the speed of the jet of water from decreasing due to air resistance.
As a result, the jet sprayed from the nozzle 71 at a high discharge speed collides with the concrete structure C without a significant decrease in speed, and the surfactant can increase the collision energy of the jet when it collides with the concrete structure C compared to the comparative example (tap water).

In addition, the reduced surface tension improves the wettability of the water jet spray liquid W, so when the water jet spray liquid W adheres to the surface of the concrete structure C, the water jet spray liquid W of Examples 1 and 3 can reduce the thickness of the water film formed on the surface of the concrete structure C. Therefore, when the water jet spray liquid W sprayed from the nozzle 71 collides with the concrete structure C through the water film, the collision energy of the jet can be prevented from being absorbed by the water film formed on the concrete structure C.

Furthermore, surfactants are used in a variety of fields and applications, and are relatively easy to obtain. Therefore, surfactants can stabilize the quality of the water jet spray liquid W compared to dissolving admixtures, which are difficult to obtain.

Therefore, the water jet spray liquid W of Examples 1 and 3 can stably improve the processing efficiency in the water jet method, even when using, for example, an existing pump unit 4.

The surfactant contains a polyalkylene glycol derivative as a main component.
According to this configuration, the polyalkylene glycol derivative has good solubility even when in powder form, for example, so that the viscosity of the water jet ejection liquid W can be made approximately equal to the viscosity of the comparative example (tap water).

Furthermore, in the case of a water jet injection fluid in which powdered polyacrylamide polymer is dissolved in water to improve processing efficiency, for example, polyacrylamide polymer is difficult to dissolve in water, so clumps of polyacrylamide polymer form in the aqueous solution and the viscosity of the aqueous solution becomes higher than that of water.

In contrast, polyalkylene glycol derivatives are less likely to form lumps in aqueous solutions due to their good solubility. Therefore, polyalkylene glycol derivatives can further homogenize the surface tension of the water jet spray liquid W and further stabilize the viscosity of the water jet spray liquid W.

Here, for example, if an aqueous solution has a higher viscosity than the comparative example (tap water), when the aqueous solution adheres to a floor or road surface, the floor or road surface becomes slippery. For this reason, when a highly viscous aqueous solution adheres to a floor or road surface, it is necessary to wash the floor or road surface with a large amount of water to remove the aqueous solution.

In contrast, the water jet spray liquid W of Examples 1 and 3, which contains a surfactant whose main component is a polyalkylene glycol derivative, has a viscosity roughly equivalent to that of the comparative example (tap water), and therefore, even if it adheres to a floor or road surface, it can prevent the floor or road surface from becoming slippery.

For this reason, the water jet spray liquid W of Examples 1 and 3 can be used to clean floors and road surfaces, reducing the effort required to remove scattered aqueous solution and waste liquid after processing the concrete structure C.

The water jet spray liquid W of Examples 1 and 3 contains a predetermined amount of surfactant dissolved therein, which provides a surface tension of 90% or less of that of the comparative example (tap water).
This configuration reliably increases the speed of the jet sprayed from the nozzle 71, and the surfactant can increase the collision energy of the jet when it collides with the concrete structure C. Therefore, the water jet spray liquid W of Examples 1 and 3 can further improve the processing efficiency in the water jet method.

The water jet spray liquid W of Examples 2 and 3 contains a water-soluble admixture dissolved therein, which is a set-retarding organic compound that delays the setting of cement.
According to this configuration, the set retarding organic compound has good solubility in water, and the specific gravity of the aqueous solution can be made higher than that of the comparative example (tap water).

Therefore, the set retarding organic compound can increase the collision energy of the jet when it collides with the concrete structure C compared to the comparative example (tap water).
As a result, the water jet spray liquid W of Examples 2 and 3 can improve the processing efficiency in the water jet method, even when using an existing pump unit 4, for example.

In addition, the water jet spray liquid W of Examples 2 and 3 can delay the setting time of the unhydrated cement by using a set-retarding organic compound, even if the slag remaining after processing the concrete structure C contains unhydrated cement. Therefore, the water jet spray liquid W of Examples 2 and 3 can reduce the effort required to clean floors or road surfaces and remove waste liquid containing slag that has adhered to the floors or road surfaces.

The set retarding organic compound is sodium gluconate (oxycarboxylate).
According to this configuration, sodium gluconate (oxycarboxylate) has high solubility in water, and therefore the specific gravity of the aqueous solution can be increased.

As a result, the set-retarding organic compound can reliably increase the collision energy of the jet when it collides with the concrete structure C. As a result, the water jet spray liquid W of Examples 2 and 3 can further improve the processing efficiency in the water jet method.

In addition, sodium gluconate (oxycarboxylate) can make the viscosity of the aqueous solution approximately equal to that of the comparative example (tap water). Therefore, even if the water jet spray liquid W of Examples 2 and 3 adheres to a floor or road surface, it can prevent the floor or road surface from becoming slippery.

The water jet spray liquid W of Examples 2 and 3 contains a predetermined amount of set retarding organic compound dissolved therein, which gives the aqueous solution a density of 1.02 g/cm ³ or more.
This configuration reliably increases the specific gravity of the aqueous solution, and therefore the set retarding organic compound reliably increases the collision energy of the jet when it collides with the concrete structure C. Therefore, the water jet spray liquid W of Examples 2 and 3 can further improve the processing efficiency in the water jet method.

The water jet spray liquid W of Examples 2 and 3 contains a predetermined amount of a set retarding organic compound dissolved therein, which provides a set time of 24 hours or more.
According to this configuration, the water jet spray liquid W of Examples 2 and 3 can sufficiently delay the setting of unhydrated cement contained in the slag, so that the water jet spray liquid W can easily ensure the time required for treating the slag.

In correspondence between the configuration of this invention and the above-mentioned embodiment,
The set retarding organic compound and hydroxycarboxylate system of this invention corresponds to sodium gluconate in the embodiment, but
The present invention is not limited to the configurations of the above-described embodiments, and many other embodiments can be obtained.

For example, in the above-described embodiment, the water jet spray liquid W is sprayed from the nozzle 71 of the spray unit 7 attached to the concrete structure C, but this is not limited to this and the water jet spray liquid may be sprayed from the nozzle of a water jet gun held by a worker.
Furthermore, although the pump unit 4 is mounted on the vehicle 3 in the embodiment, the present invention is not limited to this, and the pump unit 4 may be one that does not need to be mounted on the vehicle 3 .

In addition, in the water jet injection liquids of Examples 1 and 3, Sudox (registered trademark) DF-40 manufactured by NOF Corporation, which contains a polyoxyalkylene compound as its main component, was used as the polyalkylene glycol derivative, but this is not limited to this.

For example, it may be a surfactant other than Sudox (registered trademark) DF-40 manufactured by NOF Corporation, which contains a polyalkylene glycol derivative as its main component, or a surfactant containing an appropriate component other than a polyalkylene glycol derivative.
The polyalkylene glycol derivative may be, for example, an alkylene oxide adduct of a lower alcohol, a polyether derivative, or a glycol ether derivative.
Even in this case, the same effects as those of the water jet ejection liquids of the first and third embodiments described above can be achieved.

In addition, in the water jet spray liquids of Examples 2 and 3, sodium gluconate (oxycarboxylate) was dissolved as the set retarding organic compound, but this is not limiting, and other oxycarboxylates may also be dissolved as the set retarding organic compound.
Alternatively, hydroxycarboxylic acids (eg, gluconic acid, citric acid) or sugars (eg, glucose, sucrose) may be dissolved as the setting retarding organic compound.

With this configuration, hydroxycarboxylic acids, hydroxycarboxylic acid salts, and sugars all have high solubility in water, allowing the specific gravity of the aqueous solution to be increased. Therefore, hydroxycarboxylic acids, hydroxycarboxylic acid salts, and sugars can achieve the same effects as the water jet injection fluids of Examples 2 and 3 described above.

In addition, in the water jet spray liquid of Examples 2 and 3, sodium gluconate was dissolved in an amount that delayed the setting time, which is the start time of the hydration reaction, by 24 hours or more. However, this is not limited to this, and sodium gluconate may be dissolved in an amount that delays the reaction time of the hydration reaction by 24 hours or more, or in an amount that delays both the start time and reaction time of the hydration reaction by 24 hours or more.

Alternatively, a water jet spray liquid may be prepared by adding an abrasive to an aqueous solution containing a surfactant, an aqueous solution containing a set retarding organic compound, or an aqueous solution containing both a surfactant and a set retarding organic compound.
As a result, the water jet spray liquid can scrape a larger amount of concrete structures due to the synergistic effect of the water-soluble admixture and abrasive, thereby further improving the processing efficiency of the water jet method.

The water jet spray liquid of this embodiment can be used not only for processing concrete structures using the water jet method, but also for cleaning the surface of concrete structures or removing mortar after concrete has been poured.

71... Nozzle C... Concrete structure S... Specimen W... Water jet spray liquid

Claims (7)

A water jet spray liquid that is sprayed through a nozzle toward a concrete structure,
an aqueous solution in which a predetermined amount of a water-soluble admixture that increases the collision energy of the jet sprayed from the nozzle is dissolved;
The water-soluble admixture is
It is an organic compound that delays the setting of cement.
Water jet injection fluid. The set retarding organic compound is
At least one of hydroxycarboxylic acid, hydroxycarboxylic acid salt, and sugar
The jetting liquid for water jets according to claim 1. The density of the aqueous solution is 1.02 g/cm ³ A predetermined amount of the set retarding organic compound is dissolved.
The jetting liquid for water jets according to claim 1 or 2. A predetermined amount of the set retarding organic compound is dissolved so that the set time is 24 hours or more.
The jetting liquid for water jets according to any one of claims 1 to 3. 5. The water jet injection liquid according to claim 1, wherein the water-soluble admixture is a surfactant. The surfactant is
6. The water jet injection liquid according to claim 5 , which contains a polyalkylene glycol derivative as a main component. 7. The water jet injection liquid according to claim 5 , wherein the surfactant is dissolved in a predetermined amount to provide a surface tension of 90% or less of that of water.